feat(runtime-core) Support closures with a captured environment as host functions

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## **[Unreleased]**
 
+- [#925](https://github.com/wasmerio/wasmer/pull/925) Host functions can be closures with a captured environment.
+- [#917](https://github.com/wasmerio/wasmer/pull/917) Host functions (aka imported functions) may not have `&mut vm::Ctx` as first argument, i.e. the presence of the `&mut vm::Ctx` argument is optional.
+- [#915](https://github.com/wasmerio/wasmer/pull/915) All backends share the same definition of `Trampoline` (defined in `wasmer-runtime-core`).
 - [#921](https://github.com/wasmerio/wasmer/pull/921) In LLVM backend, annotate all memory accesses with TBAA metadata.
 - [#883](https://github.com/wasmerio/wasmer/pull/883) Allow floating point operations to have arbitrary inputs, even including SNaNs.
 - [#856](https://github.com/wasmerio/wasmer/pull/856) Expose methods in the runtime C API to get a WASI import object

lib/clif-backend/src/code.rs

@@ -763,20 +763,22 @@ impl FuncEnvironment for FunctionEnvironment {
                     readonly: true,
                 });
 
-                let imported_vmctx_addr = pos.func.create_global_value(ir::GlobalValueData::Load {
-                    base: imported_func_struct_addr,
-                    offset: (vm::ImportedFunc::offset_vmctx() as i32).into(),
-                    global_type: ptr_type,
-                    readonly: true,
-                });
+                let imported_func_ctx_addr =
+                    pos.func.create_global_value(ir::GlobalValueData::Load {
+                        base: imported_func_struct_addr,
+                        offset: (vm::ImportedFunc::offset_func_ctx() as i32).into(),
+                        global_type: ptr_type,
+                        readonly: true,
+                    });
 
                 let imported_func_addr = pos.ins().global_value(ptr_type, imported_func_addr);
-                let imported_vmctx_addr = pos.ins().global_value(ptr_type, imported_vmctx_addr);
+                let imported_func_ctx_addr =
+                    pos.ins().global_value(ptr_type, imported_func_ctx_addr);
 
                 let sig_ref = pos.func.dfg.ext_funcs[callee].signature;
 
                 let mut args = Vec::with_capacity(call_args.len() + 1);
-                args.push(imported_vmctx_addr);
+                args.push(imported_func_ctx_addr);
                 args.extend(call_args.iter().cloned());
 
                 Ok(pos

lib/llvm-backend/src/stackmap.rs

@@ -161,7 +161,7 @@ impl StackmapEntry {
                 ValueSemantic::ImportedFuncCtx(idx) => MachineValue::VmctxDeref(vec![
                     Ctx::offset_imported_funcs() as usize,
                     vm::ImportedFunc::size() as usize * idx
-                        + vm::ImportedFunc::offset_vmctx() as usize,
+                        + vm::ImportedFunc::offset_func_ctx() as usize,
                     0,
                 ]),
                 ValueSemantic::DynamicSigindice(idx) => {